Method of applying tread rubber to tires



July 30, 1935. H. J. woocK METHOD OF APPLYING TREAD RUBBER TO TIRES Original Filed June 6, 1932 6 Sheets-Sheet 1 0e oe e o 0 0 m k I mvgmon. H. J. W000 BY w-.u.w;

ATTQRN EY July 30, v H. J. WOOCK 1 METHOD OF APPLYING TREAD RUBBER TO TIRES Original Filed June 6, 1932 6 Sheets-Sheet 2 ATTORNIY y 30, 1935- H. J. woocK 2,009,599

I METHOD OF APPLYING TREAD RUBIER T. TIRES Original Filed June 6, 1952 6 Sheets-Sheet 3 G O 0 Q O O O f 36 32 23 ATTORNEY July 30, 1935. H. J. woocK ,0

METHOD OF APPLYING TREAD RUBBER TO TIRES Original Filed June a, 1932 e Sheeis-Shet 4 N a I, l I 1 V 3 g, M

I mvsmon H.c]. w'om-k y 1935. H. J. WOOCK 2,009,599

METHOD OF APPLYING TREAD RUBBER TO TIRES I Original Filed June 6, 1952 6 Sheets-Sheet 5 INVENTOR Q .DJAA:

ATTO R N EY July 30, 1935. H. JxwoocK METHOD OF APPLYING TREAD RUBBER TO TIRES Original Filed June 6, 1952 6 Sheets-Sheet 6 Wk 0 H 21 B Q Q m D g- I ATTORNEY therubber strip shall adhere with equal force Patented July so, 1935 UNITED STATES" Herbert J. Wooeh,

Mold Corporation; Lodi, cane, a corporation of originaltapplication June 0, m2, No.

Divided and this 22,1938, Serial No. 062,053

application March This invention relates to the tireretreading we is a divisional application of myco-pending application, Serial N0. 615,841, med June 8, 1932.;

. This invention has for its main object the provision of a novel method for applying bulk retread rubber to the the in the form of a number of continuous layers or wrappings so as to build up the desired tread base on the tire casing corresponding to that had with the use of camelback and eliminating the need of the same, and the obiection--- able features incident to its use.

In connection withthus applying the rubber it is necessary, in order to'obtain an emcient result, that. considerable pressure be applied-to obtain a good adhesion of the rubber with the tire, that throughout its area to the tire regardless of the rounded contour of thelatter; that the pressure shall be maintained substantialLv constant as the diameter of the tire is increased with the superimposed wrappingsrof rubberthereon; that the width of the rubber strip shall be gradually lessened as the tread is built up so that thecross sectional form of the new tread base when the rubber is completely applied approximates that.

of the finished tread. Other objects of this inventiontherefore are to provide novel'methods for obtaining the above desired ends and in a speedy.

and eilicient yet inexpensive manner.

These objects are preferably carried out by means of the machineof the cos-pending application, the essential features of which are shown in the accompam'ing drawings to illustrate my method.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Fig. l is a side view of the machine with a tire to be retreaded being advanced toward themill,

the latter being in secti0n..

Pig. 2 is a fragm ntary back view of supporting and advancing structure.

Fig. dis a sectionalview on the line 3-4 of Pig. 2.

the tire 1 Fig. 4 is an enlarged fragmentary top plan view 1 showing the strip width gauging cutting mechanism, with the rolls removed.

Pig. 5 is a front view of the same.

i Fig. .6 is a diagram showing the application of the rubber about the tire. Fig. '7 isa similar view showing the step of stopping the wrapping of-the rubber about the tire. 1 Pig. 8 is an enlarged fragmentary plan on the line 8-8 of Pig. 6 showingthe tirecompres'edor flattened against the mill rod.

ters of reference on the drawings, the numeral l.

denotes the side frames of the'mill in connection with which the horizontally disposed rolls 2 are mounted. The rolls are hollow and are heated by steam in any suitable manner and are driven so that their upper surfaces turn toward each other; The rolls are long enough so that the rubber not-being actually usedat the moment can I besrolled while the other rubber is being applied to the tire in a manner set forth later."

Gauge and trimming plates'l spaced lengthwise of the rolls and disposed toward oneend of the same are mounted above the rolls for vertical and horizontal adjustment and determine the widthof the cushion stripto be applied to the tire.- -Said plates being near one end of the rolls leave the mador portion of the latter clear for rolling the tread rubber stock to be used after the cushion stock has been applied.

Projecting horizontally from the front left hand frame I (or the one on the same side as that adjacent the above described trimming plates) are fixed upper and lower guidebars 4, between which and parallel thereto is a screw shaft 8. The bars and shaft at their opposite ends are supported by suitable standards i. The shaft .5 at its'end opposite the mill has a sliding clutch element I keyed thereon normally engaging a I ne'cted'to a control rod It which extends parallel.

to and above the as-the mill.

The bars 4 slidably support a cross head ll through which the shaft I is-threaded, so that with the rotation of said shaft one way or the other the cross head will be moved along the bars in corresponding direction. "l'heswitch and the thr'eadingof the'shaft are arranged so that when the switch arm is thrown away from the millthemotorandshai'tareturningsothatthe 4! upper bar 4 and extends as far cross head will be moved toward the mill, and vice versa.

Turnably supported from the cross head on the same side as the rolls is a cylindrical chuck device l8 adapted for detachable clamping engagement with a rim IS. on which the tire 20 to be retreaded is mounted; said tire having a flexible pressure bag 2| therein. This bag is maintained under suitable and adjustable air pressure while mounted on the rim and chuck by a flexible air conduit 22 connected to the back of the cross head and communicating with a passage leading through the chuck and which in turn is connected to a conduit 23 detachabiy coupled to the exposed valve stem'of the tire. v

The conduit 22 is connected by a pipe 24 to one port of a three-way manually controlled valve 25. Another port of the valve is connected toa pipe 26 in which a supplyof compressed air at a predetermined pressure is maintained .while the third port of the valve is connected to a pipe 21 in which a supply of air at a predetermined but different pressure is maintained. The valve is arranged so that'the pipe 24 maybe placed in communication with the'pipes' 26 and 21 selectively or shut off entirely.

,A rigid finger 28 projects upwardly from the cross head to adjacent the rod- It so as to engage either one or the other of a pair of stop collars 29 adjustably mounted on said rod. One collar is positioned so that the rod will. be shifted back to throw the switch arm I 2 to a neutral position after the'tire has been retracted from the rolls a predetermined distance with. the voperation of the motor in a corresponding" direction. The other collar is positioned so that the motor is shut off from rotation in the opposite direction, by throwing the switch arm to a neutral position with a corresponding movement of the rod l6; when the tire reaches a predetermined position relative to the front roll of the mill; 7 This position is such that the tire is flattened in cross section somewhat where it engages the roll, as shown in Figs. 6 and 8. The extent of this flattening is accurately determined for tires of different sizes and according to what expe- 35 to removably support lugs 36 which extend radially from the back of the drum in, the direction of the axis thereof. The lugs 33 are normally clear of the path of movement of the lugs 36 with relation to the rotation of the tire and its supporting structure. Said lugs however are adapted to be moved into such path by suitable means such as an air cylinder and piston unit 31.

Extending under the rolls of the mill-parallel to the shaft 5 and supported from the adjacent frame! is a shaft 38. A clutch element 39 is.

splined on the shaft, which element is adapted to engage a cooperating element 40 fixed in connection with a chain drive 4| by which driving engagement withthe adjacent end of the shaft 5 is had. At itsopposite end the shaft '38 is geared to a shaft 42 extending parallel to the rolls and disposed back of the front roll. Said shaft intermediate its ends but near the left hand end is formed with lengths of right and left hand threads as shown at 43. The opposite end of the shaft has gear connection with a hand operated shaft 44 extending to the front of the mill.

Mounted intermediate its ends on the threaded portions of the shaft 42 are arms 45 extending forwardly under the front roll 2. Each arm at its .front end carries a pair of upwardly projecting cutter elements 46 spaced lengthwise of the roll and adapted to normally engage the under face of the same adjacent its bottom central plane. When these elements are engaged with the roll they out two narrow strips N of rubber from the bulk of rubber R disposed about the roll and leave a central wide strip S of the width desired for application to the tire.

Cooperating scale and pointer elements 41 and 48 respectively are mounted in connection with the;cutter'supporting arms so that said cutters may be initially set to the desired accurate spacing by manipulation of the hand shaft 44.

Supported from the upper ends of the arms 45 in front ofthe same and of the cutters and in forwardly and downwardly angled relation to the latteriare rollers 49, of convex longitudinal curvature. These rollers are adapted to engage with the strips N so as to enable such strips to be deflected from their original positions on the roll and from the central strip S as the latter moves up from underneath for engagement with the tire. These strips N after being initially formed for a certain length' by the rotation of the rolls are caught and pulled out by the operator and engaged with the rollers. The portions of said strips above the rollers are severed from the mass of rubberand are re-engaged with the main portion of the'rubber to the sides of the main strip. Withthe further rotation of the rolls therefore said narrow strips as they are formed by the cutters will be continuouslyengaged by the rollers and will be maintained deflected, so as to be clear of the plane of contact of the tire with the roll, and thus insuring that no rubber to the sides of the main strip S can be engaged with the tire; since the roll is uncovered and clean for a certain distance on each side of the main strip.

The clutch element 38 is shifted into engagement with the element 40 at will by suitably manually controlled means so as to be driven by the shaft 5;the direction of cut of the treads 43 being such that with the rotation of the shaft 3 in a tire retracting direction, the arms 45 and the cutters 46 will be moved toward each other.

Mounted on the base-of the mill between the frames l and at the front of and below the front roll 2 is a cylindrical casing 80. This casing-4s in the'front side of the casing and is rolled about a spring actuated core 53 in the casing and of substantially the same construction as employed in the ordinary shade roller, or so that the material will be normally wound about the core and the blade held adjacent the casing. A handle 54 projects from the right hand end of the blade so that it may be easily pulled up against the resistam of the spring core.

The tire to which the tread is to be applied is first subjected to the action of a bufllng machine to remove the old tread rubber, and expose the fabric, so that a roughened surface to which the new rubber readily adheres without the need of cement,is provided].

. In operation a mass of cushion rubber suflicient for one wrappingabout the tire is'first placed in the mill so as to be rolled in a plane between the gauge plates 3. At the s'ame'time if desired a mass of tread rubber B may be placed'in the mill to the side, of theside otthe cushion rubber so as to be rolled without mixingwith the cushion stockfl'The tile 20 to be worked on, which. has been already heated in a suitable enclosure;

'is then mounted onuthe rim asfpreviously described and the bag Zi is fllled with air under pressure and maintained underfpressure until' the completion of the rubberwrapping opera tions. The rolls are set tothe desired spacing and one stop 29 is set so that'the advance of the tire wiilbe halted when it has engaged the front roll 2 and has been flattened a predetermined extent as determined by the chart on. the board SI and according to the-size of the particular tire.

The switch of themotor I0 is thn closed by manually pulling the rod- IS in the direction away fror'ngthe mill, when the accompanying operation of the motor and the rotation of the screw shaft 5 advances the tire and its supporting structure as a unit. When' the finger 28. on the cross head l'l engages the stop 29 nearest the mill and pulls the rod ii to a switch opening position, it

stops the motor and the, advance of the are; The tire is then compressed and flattened where it engages the roll for a width at least equal to that of the strip to beiappliedy Such-engagement also causes the tireto be'rotated byreasonlof itscontact with the roll andtherubber strip to be transferredfrom the roll onto the tire; the.

strip being severed onthe roll at I In the meantime: the gauge-plates l 'have beerr set to the desired spacing and depressed into contact with therolls. 'Iliefstrip as applied to the tire 'will thus be-oij-an ",even an'd {desired width; At the initial point ofcontact Of the with the; -roll, av chalk or other mark M :as'in dicated-in Figs. 6 and 7 is madejon the ,side'oi' the tires-this mark serving as a gauge 'for the 1 wrapping of the rubberthereabout. As the wrap ping of rubber one complete turn about the tire approaches thestarting pointthe operator raises 7.

the blade 5| and places the same against the face of the tire in alinernent with theumark 'M, and

so that it is between the tire and the rubber being stripped from the roll. As the-rubber from the roll reaches the starting point on the tire the operator throws the rod [6 so that the motor is A started in the reverse direction, causing the tire "to back away from the rolland giving room for the blade to be manipulated to sever the rubber between the tire and rdll so that nomore than necessary will be engaged with the tire.

The blade is then allowed to drop to its normal resting place adjacent thecasing 50 by the pull r the, length: of the material 52' thereon.

' It is to be understood that anexact termination of the wrapping is notgabsolutely necessary,"n'or is a. neat finish, since this wrapping is later cov-f V ered with the tread rubber and is never seen and in any event the finish is produced by the matrix,

in the retreading mold in which the tire is s ub sequently placed.

During the above operations the pins 31 are A held from the path oi the lugs 36; and the clutch elements 39 and 49 remain disengaged. .Also the cutters 46 are lowered from the roll, since these will turning movements beimparted to termittently backed up slightlyirom v suflicient to counteractior the thickness the cutters have nothing to do with the placing of v the cushion strip on the tire.v

with the reverseoperation of the motor, as above described, the tire continues to back away from the roll'until the flnger Il engages the adjacent stop 3! and rod al o that the operation oi the motorfis; halted; The gauge plates 3 are .then liited clear 0! the rolls and the remaining cushion rubber is stripped-from the trolls while the tread rubber is allowed to take its ,place, the roll s rotating continuously. The cutters 46 are then spaced by handf to give the strip, ,.S the desired width between the cutters.

H The cutters are moved into, engagement with the i'roll 'and with the rotation ornie latter, the

'narrowfstrips N as formed from the mass of rubber passing about the roll betweenthe pairs olcutters are caught and deflected over the rbll- 'ers 49 as previously described. This leaves the wide strip of rubber S with clean cut etkes and with uncoveredclean portions of the roll to the sides of the'stripso that there is o gimme o! I engaging and adhering to thetireh These operations being completed-and which any 'rubbervother thanthat of the strip itsel! only consume a very short time-[the motor I. is

started by manual operation 0! the rod II in a' tire advancing direction until such advancing movement is halted as before by the engagement of the finger 2! with the stops 2|, whereupon the simultaneously with the starting oithe on ping operation the. operator causes-the eonheetion between the motor II and the's haft Q to be broken, the lugs to be moved into the path oi' movement of the lugs ",and the clutchlelewill thus be rotated as the shaft I rotates, which as before stated willcause the cuttersto, be moved along said shaft 42 in one direction ortiieother;

Such rotation is intermittently imparted tb the shaft 5 acertain number of times" with each full revolution otthe tire according :to the numberot lugs it on the drum I, as said lugs engage,

and'pushpast the lugs 33 successively and thus rotate the collar "and the-shaft I to 'w Tisoid collar-is keyed. v

V The direction of rotation-oi the shaft ,I this i had relative to the direction 0! cut 0! the screw threads 43' on the shaft "is such .18 are moved closer-together.

As a result the'strip S is gradually in width asthe wraps about the tire incre'ssaso' that as :theiwraps arecompieted the one;

form of the rubber thus applied-- appl fbximates that of the finished tread. as shown in m. 9 The extent to which the widening oi'thestrips' is thus course. on the number oif lugs "used, obviously the more lugs there are the with eachi'uil revolution of thewith such rotation of the shaft [the the lessened andconsequentlythedegreeot side slope oi-the built uprubber on-the tire, depends of rubber being added and to only maintain the tire flattened for a width equal to that of the rubber strip being applied at that time. 7 V p I when the flnal wrap is aboutcompleted the operator again deflects and severs the rubbery from the'roll onto the tire by the use of the blade II as before. At about the same time the driving engagement betweenthe motor i and shaft 8 is re-established, This enables the tire to be retracted upon the motor switch being again closed by hand as was done after the cush-' ion-strip wrapping operation.

After the run retraction of the "tire and the resultant halting of the motor the tire and bag are removed from the chuck. The tire maybe then immediately placed in a mold and vulcanized to provide the finished and cured retread.

I have found that by the use of my improved method as herein disclosed,I am enabled to cause the tread'rubber to effectively adhere to'the tire without the'use' of applying an independent coat- 1 'ing of rubber'cementbetween the rubber and substantially fulflllsfthe objects of the invention as set forth herein. 7 I

Having thus described'my invention what I claim as new and useful and desire to secure by Letters Patent is;

' 1. Themethodof'applying tread rubber to a pneumatic tire from'a roll, consisting in forcing a tire free'torotate against the'rollwith a pressure sufficient toflatten the tire transversely to a predetermined extent, maintaining" the tire under a predetermined internal pressure while it is thus held flattened, and forming .a strip of rubber on the roll forfengagement with said flatf tened' portion.

2. The method of applying'tread rubber to a, pneumatic tire froma roll consisting in inflating f the tire, holding the tire againstthe roll while" "with a predetermined initial pressure, rotating permitting the theta rotate withthe'roll, forming a strip of rubber on the roll withthe rotation thereof in the lateral plane of the tire for wrapping engagement therewith, causing such wrapping to take place, lessening the width of' the strip at'intervals as the wrappin'gs become superimposed on each other, and retracting the tire I from th'eroll to a predetermined extent coincident with each widthelessening operation,

3. The. method of applying tread rubber to a pneumatic tire froma roll consisting-in inflating the tire, holding thetire againsttheroll while permitting the tire to rotate, the, roll, forming a strip of rubber on the roll with the rotation thereof in the lateral plane of the tire for wrapping engagement therewith, causing such wrapping to take place, and retracting the tire from the roll a predeterminedextent with the superimposing of successive wrappings of the strip on the tire.

Y The method of applying tread rubber to a pneumatic tire fromaroll, consistin'gin forcing a' the free torotate against the roll with a pres sure sufllcient to flatten the .tire transversely to a predetermined extent, maintaining the tire under a predetermined internal pressure while it isthus held flattened, forming a strip of rubber on the roll the width of said flattened portion for direct engagement therewith, gradually le'ssen- I tire with equal pressure the tire, and coincidently retracting the tire from the roll to an extent suiilcient to maintain the width of the flattened portion substantially equal to the width of the strip.

"5 .'The method oi" applying tread rubber to a pneumatic tire from a roll, consisting in inflating the tire, and forcing the tire while still free to rotate, against the rubber on theroll, with a pressure suflicient to flatten the tire transversely toe predetermined extent and thus cause the rubber'to be appliedagainst and adhered to the p throughout the width of the flattened,,portion.

6. The method of applying tread rubber to a the from a'sheet on a roll consisting in rotatably engaging the tire with the roll, cutting a strip 'from the sheetin the lateral plane of and for application to the tire with the rotation of the roll, placing a separating element against the tire and between the strip and the tire at "the point of beginning of the wrap to prevent further wrapping after the strip has reached the point of beginning of the wrap,.and severing the strip at such point.

'I. The method of applying rubber about a pneumatic'tire comprising flattening the tire for a limited area of its circumference and width progressively, Tandapplying astrip of rubber to said area as itis formed. 1 8. The method of applying rubber about a pneumatic tire comprising flattening, the tire for a limited area ofits circumference and width progressively, and applying a strip of rubber to said area'as it is formed, and against theresistance of a predetermined pressure.

9; The methodof applying rubber about a pneumatic 'tire comprising flattening the tire for a limited area of itscircumference and width progressively, and applying a strip of rubber to saidarea as it is progressively formed, and so as t'o'extend completely about thetire in the form .of a number of wrappings. and reducing the ex- I tent of flattening with the successive wrappings.

the'roll'and tire, feeding a strip of cushion stock between theroll and tire so that said strip will adhere to and extend about the. tire with the rotation thereof, reducing the pressure between the roll and tire, and'feeding a strip of tread rubber between the roll and tire for adhesion to the cushion strip. t

11. The method of'b'uliding up a tread on a tire consisting in holding the tire while free to rotate against a rotatingroll of a mill, rolling cushion stock in the mill and applying it to the tire, simultaneously rolling cushion stock in the mill, while maintaining the same clear of the cushion stock and carcass, backing the tire away from the roll afterjthe cushion stock is applied, stripping thereniaining cushion stock from the 'mill, shifting the'rolled tread stock in the mill against the roll to cause the stock to be applied aboutthe tire in contact with the cushion "stock thereon.

12. The method of building up a tread on a tire consisting in simultaneously rolling masses, of cushion and tread stock rubberin a mill, maintainingthe stocks separated, and successively advancing a tireagainst a roll of the mill to contact the rolled cushion and tread stocks in the proper sequence.

- 13. That method of applying rubber to a tire 'ment with the roll, forming a' strip oi carcaastormedintoailnishedtireotsuhstantially circular cross section, comprising the steps of applying a yieldable pressure to the interior 0! the carcass, flattening the curved tread of the carcass against said pressure progressively around the entire periphery oi the carcass ,-pressin'g rubber onto the carcass in the plane of theflattened portion, and continuing such application of rubher until the latter is built up to a desired thick- 14. That method of applying rubber to a tire carcass formed into a flnished tire of substantially circular cross section, comprising the steps of applying a yieldable pressure to the interior' of the carcass, rotating the carcass, flattening thecurvedtreadolthccarcassagainstsuchinternal pressure at a point in its circle or rotation, then pressing rubber onto the carcass in the plane oi the flattened portion thereoi' and continuing such application 0! rubber until .the latter is built up on the carcass to a desired thickness.

15. That method or applying rubber to a tire carcass formed into a flnished tire oi substantially circular cross section consisting in the steps or flrst applyins a yieldable prmsure to the interior ot'the carcass, moving the carcass under suchpressureagainstarolluntilthecurvedtread otthetireisflattenedintheplaneoiitsma'alethe roll, and transferring such strip ol rubber i'romtherolltothecarcassatthepointci'eon tact between the carcassand roll.

18. That-method oi apply nl rubber to a pneu- I matictirecarcassconsistinginthestepsoiflrat applying a yieldable pressure to the interior at thecarcass,movingthecarcassundersuchpres-.. sureagainstarolluntiltheiaceoithetireia flattened in the plane or its engagement with 1. the roll, Iorming a strip of rubber on the roll.

tothe carcass atthepointoicontact between the carcass and roll. and gradually retracting the tiretromtherollasthetransierredstripotmbll ber builds up on the tire. 7

17. That method or applying a strip of rubber, which is initially substantially flat'in cross section, about the tread of a tire carcass which is initially substantially circular in cross section, which method comprises the steps of temporarily flattening the circular tread oi the carcass to cause it to substantially conform to the flat o! the strip, and applyin the flat strip to the tread of the carcass while the latter is in its temporarily flattened form.

H IRBIRT J. WOOCK. 

